Some Cohomotopy Groups of Suspended Projective Planes

In this paper we compute some cohomotopy groups of the suspended complex and quaternionic projective plane by use of the exact sequence associated with the canonical cofiber sequence and a formula about a multiple of the identity class of the suspended projective plane.</p

Effect of field damping layer on two step absorption of quantum dots solar cells

Multi-stacked InAs/AlGaAs quantum dot solar cells (QDSCs) introduced with field damping layers (FDL) which sustain the junction built-in potential have been studied. Without an external bias condition, the external quantum efficiency (EQE) of QD layers are reduced by introducing the thick FDL, because the carrier escape due to built-in electric field was suppressed. On the other hand, the photocurrent production due to two-step absorption is increased by the formation of flat-band QD structure for QDSC with thick FDL

Vers l'évaluation des données pariétales fluctuantes avec des méthodes de frontières immergées

International audienceImmersed boundary conditions (IBC) has reached a sufficient level of maturity to allow the simulation of compressible high Reynolds number flows around complex geometries. However, the reconstruction of physical quantities at the wall of geometries introduced using IBC is far from being straightforward. The difficulty to obtain a prediction as accurate as for classical body-fitted approaches originates from the intrinsic mismatch between immersed boundaries and the underlying mesh. To tackle this issue, a novel method to compute global loads and to provide precise wall data in the view of spectral analyses is introduced. First, this method is assessed for the investigation of highly unsteady separating compressible flows of two space launcher afterbody configurations using Zonal Detached Eddy Simulation (ZDES). Then, the results are compared against validated numerical simulations using a classical body-fitted approach. Finally, the present method successfully returns wall quantities with IBC consistent with classical methodologies and without additional time-consuming operations.Les méthodes de frontières immergées ont atteint un niveau suffisant de maturité pour permettre la simulation des écoulements compressibles à haut nombre de Reynolds sur des géométries complexes. Cependant la reconstruction des valeurs pariétales introduites pas une approche de frontières immergées est un problème complexe. La principale difficulté provient de la dissociation intrinsèque à la méthode entre le maillage de fond utilisé durant la simulation et l’objet immergé. Afin de résoudre ce problème, une nouvelle méthode a été développée afin de permettre le calcul des efforts aérodynamiques et de permettre l’analyse spectrale des données pariétales sur une paroi modélisée par une approche de frontières immergées. Cette méthode a été appliquée afin de simuler l’écoulement autour de deux arrière-corps de lanceurs spatiaux en utilisant la Zonal Detached Eddy Simulation (ZDES). Les grandeurs pariétales fluctuantes sur les parois modélisées par une approche de frontières immergées ont été comparées à des calculs obtenus par des méthodes classiques. Les résultats ont montré que l’approche proposée permet d’évaluer les grandeurs pariétales modélisées par des approches de frontières immergées

One-neutron knockout reaction of 17C on a hydrogen target at 70 MeV/nucleon

First experimental evidence of the population of the first 2- state in 16C above the neutron threshold is obtained by neutron knockout from 17C on a hydrogen target. The invariant mass method combined with in-beam gamma-ray detection is used to locate the state at 5.45(1) MeV. Comparison of its populating cross section and parallel momentum distribution with a Glauber model calculation utilizing the shell-model spectroscopic factor confirms the core-neutron removal nature of this state. Additionally, a previously known unbound state at 6.11 MeV and a new state at 6.28(2) MeV are observed. The position of the first 2- state, which belongs to a member of the lowest-lying p-sd cross shell transition, is reasonably well described by the shell-model calculation using the WBT interaction.Comment: 15 pages, 3 figure

Neutron Diffraction Study of Nickel in the Liquid State

The structure of nickel in the liquid state has been studied by neutron diffraction at 1500℃. After calculating the interference function (Fourier analysis), the atomic radial distribution function was evaluated from which interatomic distance and coordination number were obtained

14Be(p,n)14B reaction at 69 MeV in inverse kinematics

A Gamow-Teller (GT) transition from the drip-line nucleus 14Be to 14B was studied via the (p,n) reaction in inverse kinematics using a secondary 14Be beam at 69 MeV/nucleon. The invariant mass method is employed to reconstruct the energy spectrum. A peak is observed at an excitation energy of 1.27(2) MeV in 14B, together with bumps at 2.08 and 4.06(5) MeV. The observed forward peaking of the state at 1.27 MeV and a good description for the differential cross section, obtained with a DWBA calculation provide support for the 1+ assignment to this state. By extrapolating the cross section to zero momentum transfer the GT-transition strength is deduced. The value is found to compare well with that reported in a beta-delayed neutron emission study.Comment: 5 pages, 2 figure